Whatever luxury accessory from the czars’ households that an American collector could desire, Armand Hammer could probably make it materialize. In the 1920s and ’30s Hammer, the manufacturing tycoon, helped supply Western currency to the Soviets, in exchange for their loot of aristocrats’ Fabergé jewelry, Easter eggs, picture frames and stone animals.

His Manhattan gallery told buyers that the wares had belonged to royalty, whether or not that was true. His picture frames came with Romanov portraits clipped from postcards and newspapers. He used Fabergé hallmarking tools to reattribute early 1900s pieces made by other Russian goldsmiths or their French archrival Cartier.

“He was playing a rather shady role at the time,” said Géza von Habsburg, the main curator of “Fabergé Revealed,” a retrospective that opens on July 9 at the Virginia Museum of Fine Arts in Richmond. Hammer’s records of the transactions seem to have vanished. “They were probably very wisely destroyed,” Mr. von Habsburg said, during a recent interview at his suburban New York home.

He has spent two years poring through hundreds of Fabergé pieces and forgeries that he calls “Fauxbergé” in the museum’s collection. Most came from a 1947 bequest by Lillian Thomas Pratt, the wife of a General Motors executive in Virginia. She happily went into debt while collecting mainly through Hammer and A La Vieille Russie gallery in New York.

“The little frame with the diamonds seems to haunt me so,” she wrote to A La Vieille Russie in 1935 while placing an order.

Mr. von Habsburg’s research team has scoured assorted European archives for new clues about the collection. Bilingual invoices for Fabergé have emerged: one page in Russian for Nicholas II, and the other in German for his Hessian wife, Alexandra.

The bad news for the Richmond museum: Most of Mrs. Pratt’s two dozen flowers made of semiprecious stones like nephrite and bowenite are Fauxbergé. The telltale signs, the curator explained, include clunky arrangements of plant stalks and rigidly outstretched pistils.

The good news: An 1890s enameled Fabergé frame, with a yellow-and-white star and seed pearls around a photo of Grand Duchess Tatiana, really did belong to the last czar. Hammer had told Mrs. Pratt that it came from the Alexander Palace near St. Petersburg, Russia. But the memento actually traveled with the family members to their Siberian deathbeds. The head executioner listed it in an inventory of their possessions.

The Virginia Museum has borrowed from a few other collections including the estate of Matilda Geddings Gray, a Louisiana philanthropist who owned Fabergé eggs full of tiny paintings of the czars’ palaces. (The Metropolitan Museum of Art will be borrowing her holdings, which had long been on view at the Cheekwood Botanical Garden and Museum of Art in Nashville.) Arthur and Dorothy McFerrin, chemical magnates in Texas who have been avidly buying Fabergé since 2005, have lent pieces that they acquired in 2009 at Sotheby’s in London. At the auction heirs of Maria Pavlovna, an aunt of Nicholas II, sold about 100 of her bejeweled cigarette cases and cufflinks.

The McFerrins’ cigarette cases, made of palisander wood, chartreuse enamel, diamonds and gold, cost up to about $1 million each at Sotheby’s.

The Pavlovna trove turned up three years ago in a forgotten vault in Stockholm; Swedish diplomats had protected it from Bolshevik looters. The provenance and authenticity are ironclad, which is rarely the case for Fabergé that appears out of the blue.

“Of any 10 pieces sent to me as digital images,” Mr. von Habsburg said, “more than nine are forgeries.”